Pengfei Fu

H-bonding assisted template synthesis of a novel ladder-like organo-bridged polymethylsiloxane

Abstract A novel soluble aryl amide-bridged ladder-like polymethylsiloxane (ALPS) was synthesized via a stepwise coupling polymerization by means of H-bonding self-assembling template. The new monomer N,N′-di(4-methyldiethoxysiloxyl-phenyl)-terephthaloyl amide, prepared by dehydrocoupling reaction of N,N′-di(4-hydroxy-phenyl)-terephthaloyl amide with methyldiethoxysilane, was hydrolyzed in a dilute solution at low temperature to form a proposed ladder-like supramolecular intermediate through amido H-bonding interaction, which was further condensed to form polymer ALPS using dibuthyltindilaurate as catalyst. A combination of techniques including 1H NMR, 29Si NMR, FTIR, X-ray diffraction (XRD), DSC, and light scattering were used to characterize the titled polymer ALPS. The results indicate the polymer ALPS possesses an ordered ladder-like architecture.

A novel tube-structure entrapped curing accelerator for prolonging the shelf-life of epoxy resin-based microelectronic packaging material

A new curing system used for prolonging the shelf-life of epoxy resin-based microelectronic packaging material (E-MPM) was first prepared by an in situ tubing/entrapping method. Based on supramolecular interactions a curing accelerator (C) for epoxy resin, boron trifluoride–pyridine (BF3·Py), has been trapped into the pores of polyorganosiloxane (POS) containing a nanoscale tubular structure, which is prepared by hydrosilylation of two reactive, cis-isotactic ladderlike polyallylsilsesquioxane (Allyl-T) molecules with two reactive, α,ω-coupling agents (1,1,3,3-tetramethyldisiloxane, H-MM) in two plus two (2 + 2) mode using Cp2PtCl2 as catalyst. Various characterizations including optical polarized microscopy (OPM) observations, differential scanning calorimetry (DSC) measurements, storage and curing tests and molecular mechanical simulation are combined to confirm that the accelerator BF3·Py is simultaneously trapped during the formation of POS and moreover, to indicate that entrapment of the accelerator C with POS is a promising alternative way to prolong the shelf-life of the E-MPM at ambient temperature.